blob: 0cf1ad7419fada8d28b7eccb4572a741857f8f6e (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
|
/*
* Written by J.T. Conklin <jtc@netbsd.org>.
* Public domain.
*/
#include <machine/asm.h>
RCSID("$NetBSD: s_ilogb.S,v 1.5 1995/10/12 15:53:09 jtc Exp $")
ENTRY(__ilogb)
fldl 4(%esp)
/* I added the following ugly construct because ilogb(+-Inf) is
required to return INT_MAX in ISO C99.
-- jakub@redhat.com. */
fxam /* Is NaN or +-Inf? */
fstsw %ax
movb $0x45, %dh
andb %ah, %dh
cmpb $0x05, %dh
je 1f /* Is +-Inf, jump. */
fxtract
pushl %eax
cfi_adjust_cfa_offset (4)
fstp %st
fistpl (%esp)
fwait
popl %eax
cfi_adjust_cfa_offset (-4)
ret
1: fstp %st
movl $0x7fffffff, %eax
ret
END (__ilogb)
weak_alias (__ilogb, ilogb)
|